Ocean, nature, critters, and recreation

Sep 15, 2011

Shrinking ice forces thousands of walruses ashore in Alaska

The polar bear may be the sympathetic poster child to illustrate the effects of vanishing Arctic sea ice, but the plight of the Pacific walrus is similar and nothing illustrates that better than a video being shared by the U.S. Geological Survey's Alaska Science Center.

It reveals an astonishing 20,000 walruses massed together on the northwest coast of Alaska, at a time when they ought to be far offshore and using ice platforms to rest upon between foraging missions in the Chukchi Sea.

With ice this year near an all-time recorded low, the tusked mammals have increasingly sought the refuge of land, taking them far from feeding grounds and altering their behavior. Younger, smaller walruses are in danger of being crushed as larger walruses jockey for territory in the haulout on the barren coast near the village of Point Lay.

Long swims to offshore feeding areas -- walruses typically forage on the sea floor for shrimp, crabs, sea cucumbers and small mollusks -- might stress even the strongest of the mammals.

"They become a little more restricted in the areas they can forage, because they now can access only what's available from shore," Science Center biologist Chad Jay told the Los Angeles Times, adding that some radio-collared walruses are swimming as far as 40 miles to find food.

An adult walrus requires about 100 pounds of food per day, so its day is full even under ideal conditions, with ice platforms immediately above or very close to prime feeding areas.

This represents the fourth year of the giant haulout near Point Lay, for an animal whose population may number about 130,000 animals and is under consideration for endangered species protection.

But unlike the past three years more animals have tried relocating north of Point Lay, beyond traditional areas, where there is no ice and, thus, no suitable habitat, especially for calves that are reliant on their mothers.

Jay stated: "We're wondering what they're going to do, because they're spending their time in the water while they're out there. If the weather gets up, it could exhaust the animals. The calves are totally dependent on the mother for protection, and the calves are also hitching a ride on the mother when they're traveling, and sometimes the mother and calf can get separated."

A few dead calves were spotted during the aerial survey of the Point Lay haulout, and last year several calf carcasses remained after the walruses left for their fall-winter grounds on pack ice in the Bering Sea.

Scientists, meanwhile, continue to study the impacts of dwindling ice on walruses and other animals that inhabit Arctic waters.